/in/foo.cc: In member function 'void Str::Index(char*, int, char*)':
/in/foo.cc:40:12: error: return-statement with a value, in function returning 'void' [-fpermissive]
   return i-j;
            ^
/in/foo.cc:42:11: error: return-statement with a value, in function returning 'void' [-fpermissive]
   return -1;
           ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:49:9: error: expected primary-expression before ']' token
  cin>>s[];
         ^
/in/foo.cc:50:7: error: 't' was not declared in this scope
  cin>>t[];
       ^
/in/foo.cc:50:9: error: expected primary-expression before ']' token
  cin>>t[];
         ^
/in/foo.cc:52:19: error: 'strlen' was not declared in this scope
  int tlen=strlen(t);
                   ^
/in/foo.cc:56:22: error: 'Index' was not declared in this scope
   k=Index(s,k+tlen, t);
                      ^
/in/foo.cc:61:10: error: no matching function for call to 'Str::Index()'
  s.Index();
          ^
/in/foo.cc:29:6: note: candidate: void Str::Index(char*, int, char*)
 void Str::Index(char s[], int si, char t[])
      ^~~
/in/foo.cc:29:6: note:   candidate expects 3 arguments, 0 provided